Single sided stretch bonded laminates, and methods of making same

ABSTRACT

An elastic laminate capable of being rolled for storage and unwound from a roll when needed for use, includes an elastic layer of an array of continuous filament strands with meltblown deposited on the continuous filament strands, and a facing layer bonded to only one side of the elastic layer. The meltblown layer may include an elastic polyolefin-based meltblown polymer having a degree of crystallinity between about 3% and about 40%. The laminate suitably has an inter-layer peel strength of less than about 70 grams per 3 inches cross-directional width at a strain rate of 300 mm/min. Alternatively or additionally, the continuous filament strands and/or the facing layer may include an elastic polyolefin-based meltblown polymer having a degree of crystallinity between about 3% and about 40%. In certain embodiments, the elastic laminate may include an extensible facing layer bonded to an elastic or semi-elastic film layer having a basis weight of about 50 gsm or less, wherein the facing layer includes an elastic polyolefin-based polymer having a degree of crystallinity between about 3% and about 40%.

RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 10/750,295, filed 31 Dec. 2003 now U.S Pat. No. 7,601,657. Thedisclosure of the prior application is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to continuous filament and film-basedstretch bonded laminate materials for use on or in various personal careproducts, and other products requiring stretch capability, andmanufacturing methods for making such stretch bonded laminate materials.

BACKGROUND OF THE INVENTION

The term “stretch bonded laminate” refers to a composite elasticmaterial made according to a stretch bonding lamination process, i.e.,elastic layer(s) are joined together with additional facing layers whenonly the elastic layer is in an extended condition (such as by at leastabout 25 percent of its relaxed length) so that upon relaxation of thelayers, the additional layer(s) is/are gathered. Such laminates usuallyhave machine directional (MD) stretch properties and may be subsequentlystretched to the extent that the additional (typically non-elastic)material gathered between the bond locations allows the elastic materialto elongate. One type of stretch bonded laminate is disclosed, forexample, by U.S. Pat. No. 4,720,415 to Vander Wielen et al., in whichmultiple layers of the same polymer produced from multiple banks ofextruders are used. Other composite elastic materials are disclosed inU.S. Pat. No. 5,385,775 to Wright and copending U.S. Patent PublicationNo. 2002-0104608, published 8 Aug. 2002, each of which is incorporatedby reference herein in its entirety. Such stretch bonded laminates mayinclude an elastic component that is a web, such as a meltblown web, afilm, an array/series of generally parallel continuous filament strands(either extruded or pre-formed), or a combination of such. The elasticlayer is bonded in a stretched condition to two inelastic or extendablenonwoven facing materials, such that the resulting laminate is impartedwith a textural feel that is pleasing on the hand. In particular, theelastic layer is bonded between the two facing layers, such that thefacing layers sandwich the elastic layer. In some instances, thegatherable facing layers may also be necked, such that the stretchbonded laminate is actually a necked stretch bonded laminate that mayhave some extension/elasticity in the cross-machine direction (CD).

To “neck” or “necked” refers to a process of tensioning a fabric in aparticular direction thereby reducing the width dimension of the fabricin the direction perpendicular to the direction of tension. For example,tensioning a nonwoven fabric in the MD causes the fabric to “neck” ornarrow in the CD and give the necked fabric CD stretchability. Examplesof such extensible and/or elastic fabrics include, but are not limitedto, those described in U.S. Pat. No. 4,965,122 to Morman et al. and U.S.Pat. No. 5,336,545 to Morman et al. each of which is incorporated hereinby reference in its entirety.

“Neck bonding” refers to the process wherein an elastic member is bondedto a non-elastic member while only the non-elastic member is extended ornecked so as to reduce its dimension in the direction orthogonal to theextension. “Neck bonded laminate” refers to a composite elastic materialmade according to the neck bonding process, i.e., the layers are joinedtogether when only the non-elastic layer is in an extended/neckedcondition. Such laminates usually have cross directional stretchproperties. Further examples of neck-bonded laminates are such as thosedescribed in U.S. Pat. Nos. 5,226,992, 4,981,747 to Morman and U.S. Pat.No. 5,514,470 to Haffner et al., each of which is incorporated byreference herein in its entirety.

“Neck-stretch bonding” generally refers to a process wherein an elasticmember is bonded to another member while the elastic member is extended(such as by about 25 percent of its relaxed length) and the other layeris a necked, non-elastic layer. “Neck-stretch bonded laminate” refers toa composite elastic material made according to the neck-stretch bondingprocess, i.e., the layers are joined together when both layers are in anextended condition and then allowed to relax. Such laminates usuallyhave multi-directional stretch properties.

Such stretch bonded laminates may be used to provide elasticity tovarious components of a personal care product and with the added benefitof a pleasant fabric-like touch, such as a diaper liner or outercover,diaper waist band material, diaper leg gasketing (cuff) material, diaperear portions (that is, the point of attachment of a fastening system toa diaper), as well as side panel materials for diapers and childtraining pants. Since such materials often come in contact with skin ofa human body, it is desirable that such materials be relatively soft tothe touch, rather than rubbery in their feel (a sensation common forelastic materials). Such materials may likewise provide elasticity andcomfort for materials that are incorporated into protective workwear,such as surgical gowns, face masks and drapes, labcoats, or protectiveoutercovers, such as car, grill or boat covers.

While such soft and stretchy materials have assisted in making suchelastic materials more user-friendly, there is still a need for suchproducts that provide even more of a cloth-like fabric feel. In thisregard, there is a need for such materials that provide even higherlevels of gathering. Further, there is a need for such laminate productswith even greater flexibility as a result of reduced overall basisweight. There is likewise a need for a laminate material that providesreduced stiffness as a result of the elimination of one facing layer onthe laminate and the use of lower basis weight elastic layer components.Such a laminate would be more efficient in its use as an elasticmaterial, plus the elimination of one facing layer would becost-effective. Such a laminate could provide ease of use/extension,with better ability to retract since there would be no drag of extrafacing layers. Essentially, such a laminate would provide for higherlevels of retraction with lower weights of polymer. However, even withall of these perceived benefits, to date a single sided stretch bondedlaminate (that is a stretch bonded laminate with a gatherable facinglayer on only one side) has been elusive because of manufacturingchallenges.

In utilizing stretch bonded laminates that themselves incorporate anadhesive component, it has been desirable to select adhesives that donot add to the stiffness of the material. Such stiffness has a negativeimpact on the overall feel of the product and the ability of the productto provide stretch attributes when in use. It therefore would bedesirable to develop additional adhesive arrangements that would notnegatively impact laminate material feel and performance, while stillallowing for the formation of a single sided material.

Many adhesives are typically somewhat elastic themselves, and tend toretain some level of tackiness even after they are dried or cured. As aresult, because of their inherent tackiness, it has been necessary, atleast with respect to filament, film, and web based stretch bondedlaminates, to utilize facings on both sides of the center elasticcomponent (i.e. filament array), so as to avoid roll blocking duringprocessing/storage. For the purposes of this application, the terms“roll blocking” and “roll sticking” shall be used interchangeably, andshall refer to the propensity of tacky films, tacky filament arrays orother tacky sheet materials to stick to themselves upon being rolled upfor storage, prior to final use. Such roll blocking may prevent use ofthe material contained on a roll as a result of the inability to unwindsuch rolled material when it is actually needed. In filament-basedstretch bonded laminates, adhesive is often applied to the facing layersthemselves, and then the facing layers are combined in a nip with thefilament array between them. Such an arrangement may generally bedescribed as an ABA laminate, where A is a facing layer and B is anelastic layer.

While it would be desirable to reduce the basis weight of the stretchbonded laminate such that the material is less costly and more flexible,it has been heretofore unclear how to eliminate the extra facinglayer(s) without causing the rolled material to stick, if it is to bestored prior to use. It is therefore desirable to have a single sidedstretch-bonded laminate that demonstrates acceptable elasticperformance, but that is also capable of being stored on a roll withoutconcern for roll blocking. It is also desirable to have a material thatmay be maintained on a roll under acceptable storage conditions, such asfor a given period of time, and at a range of temperatures. It is tosuch needs that the current invention is directed.

SUMMARY OF THE INVENTION

An elastic laminate capable of being rolled for storage, and unwoundfrom a roll when needed for use, includes an elastic layer of an arrayof continuous filament strands with meltblown deposited on thecontinuous filament strands, and a facing layer bonded to only one sideof the elastic layer. The elastic laminate includes an elasticpolyolefin-based polymer having a degree of crystallinity between about3% and about 40%, or between about 5% and about 30%. The elasticpolyolefin-based polymer may have a melt flow rate between about 10 andabout 600 grams per 10 minutes, or between about 60 and about 300 gramsper 10 minutes, or between about 150 and about 200 grams per 10 minutes;a melting/softening point between about 40 and about 160 degreesCelsius; and/or a density from about 0.8 to about 0.95, or about 0.85 toabout 0.93, or about 0.86 to about 0.89 grams per cubic centimeter. Theelastic polyolefin-based polymer may include polyethylene,polypropylene, butene, or octene homo- or copolymers, ethylenemethacrylate, ethylene vinyl acetate, butyl acrylate copolymers, or acombination of any of these polymers. The elastic polyolefin-basedpolymer may be used to form the meltblown layer, the continuous filamentstrands, and/or the facing layer.

The elastic laminate may further include an adhesive that demonstrates arelatively short open time deposited between the array of continuousfilament strands and the meltblown layer, or between the elastic layerand the gatherable facing layer. In certain embodiments, the elasticlaminate may include a nonblocking agent layer deposited on the elasticlayer, on a side opposite to the facing layer; however, a nonblockingagent layer is not necessary when the meltblown layer includes theelastic polyolefin-based polymer.

More particularly, when the meltblown layer includes the elasticpolyolefin-based polymer, the elastic laminate suitably has aninter-layer peel strength of less than about 70 grams per 3 inchescross-directional width at a strain rate of 300 millimeters/minute(mm/min). For example, when the elastic laminate is rolled upon itself,it can be unwound for future use and demonstrates a peel strength from aroll (while it is being unwound) of less than about 70 grams per 3inches cross-directional width at a strain rate of 300 mm/min. In yetanother alternative embodiment, such elastic laminate demonstrates apeel strength from a roll of less than about 60 grams per 3 inchescross-directional width at a strain rate of 300 mm/min. In yet anotheralternate embodiment, such elastic laminate demonstrates a peel strengthfrom a roll of less than about 50 grams per 3 inches cross-directionalwidth at a strain rate of 300 mm/min. Thus, the elastic laminate may notrequire any post-calender treatment such as a nonblocking agent or thelike.

In still a further alternative embodiment, the elastic laminate includesan adhesive between the array of continuous filament strands and themeltblown layer, or between the facing layer and the elastic layer, thatdemonstrates an open time of between about 0.2 seconds and 1 minute, orbetween about 0.2 seconds and 3 seconds, or between about 0.5 secondsand 2 seconds. In still another alternative embodiment, such elasticlaminate includes an adhesive between the array of continuous filamentstrands and the meltblown layer, or between the facing layer and theelastic layer, wherein the adhesive is applied in an amount less thanabout 16 gsm, or less than about 8 gsm, or less than about 4 gsm, orbetween about 1 and 4 gsm. In still another alternative embodiment, thelaminate includes an adhesive between the facing layer and the elasticlayer, and also on a side of the elastic layer opposite to that of thefacing layer. In still a further alternative embodiment, such adhesiveis distributed in similar add-on amounts between the facing layer andthe elastic layer and also to the side of the elastic layer opposite tothat of the facing layer.

The meltblown layer in the elastic layer may be a single layer ofmeltblown material or, alternatively, may include two or more layers.For example, one of the layers may include an elastic polyolefin-basedmeltblown polymer having a degree of crystallinity between about 3% andabout 40%, or between about 5% and about 30%, and another layer mayinclude a styrenic block copolymer-based meltblown polymer.

The meltblown layer may be present within the elastic laminate at anadd-on up to about 34 grams per square meter (gsm), or between about 1and about 5 gsm, or between about 1.25 and about 2.5 gsm, at the pointof lamination.

In still another alternative embodiment of the invention, the elasticlayer has an overall basis weight up to about 54 gsm. In still anotheralternative embodiment of the invention, the elastic layer has a basisweight of between about 4 gsm and 23 gsm, or between about 10 gsm and 18gsm.

In still another alternative embodiment of the invention, the facinglayer has a basis weight of between about 0.3 and 1.5 osy. In yetanother alternative embodiment of the invention, the facing layer isselected from the group consisting of nonwoven webs, nonwoven weblaminates, foams, scrims, netting, films, and combinations thereof. Inyet another embodiment of the invention, the single gatherable facinglayer is necked. In certain embodiments, the facing layer may include aspunbond-meltblown-spunbond laminate in which the meltblown layerincludes an elastic polyolefin-based polymer and is positioned betweentwo spunbond layers.

In yet another alternative embodiment of the invention, an extensiblefacing layer is bonded to an elastic or semi-elastic film having a basisweight of about 50 grams per square meter (gsm) or less, or betweenabout 35 to about 45 gsm, or between about 38 and about 42 gsm. The filmand/or the facing layer(s) may include an elastic polyolefin-basedpolymer as described herein. The laminate displays greater retractionthan comparable laminates having two conventional facing layers. Thelaminate may also include elastomeric strands. As a further alternative,the laminate may include a second extensible facing layer bonded to theopposite surface of the film.

In an alternative embodiment, a method for forming a stretch bondedlaminate includes forming an elastic layer by applying an elasticmeltblown polymer to an array of continuous filament strands; stretchingthe elastic layer; bonding a gatherable facing layer to the stretchedelastic layer adjacent to the meltblown layer while the stretchedelastic layer is in a stretched condition, to form a stretch bondedlaminate; and allowing such stretched bonded laminate to retract. Asingle side facing stretch bonded laminate (which term shall be usedsynonymously with single sided stretch bonded laminate) made by themethod, for use in a personal care or other stretchable article is alsocontemplated by the invention.

In another alternative embodiment, a method for forming a single facingstretch bonded laminate includes providing an elastic layer; applying ameltblown nonblocking agent to one side of the elastic layer; stretchingthe elastic layer; bonding a gatherable facing layer only to thestretched elastic layer on a side opposite to the meltblown nonblockingagent while the stretched elastic layer is in a stretched condition, toform a single sided stretch bonded laminate; and allowing such stretchedbonded laminate to retract.

In a further alternative embodiment, a method for forming a single sidedstretch bonded laminate includes providing an elastic layer; stretchingthe elastic layer; bonding a gatherable facing layer to only one side ofthe stretched elastic layer while the stretched elastic layer is in astretched condition to form a stretch bonded laminate by using anadhesive with a relatively short open time, and that is not tackyfollowing curing; and allowing such stretched bonded laminate toretract. In still a further alternative embodiment, the adhesive isapplied to bond the elastic layer to the single gatherable facing layerboth prior to contacting the elastic layer with the facing layer(prebonding adhesive application) and following contacting the elasticlayer with the facing layer (postbonding application). The prebondingadhesive application is applied prior to the elastic layer and facinglayer being brought together into a laminate. In one embodiment, thepostbonding adhesive application is applied to the filament side of thelaminate, after the elastic layer and facing layer have been laminated.In a further alternative embodiment, similar amounts of adhesive areapplied in both the prebonding and postbonding adhesive applications. Itis contemplated that the invention also includes a single sided stretchbonded laminate made by such adhesive methods and articles made fromsuch laminates.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood by reference to the followingdescription of embodiments of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 illustrates a method of manufacturing a single sided stretchbonded laminate in accordance with the invention.

FIG. 2 illustrates a cross sectional view of one embodiment of a singlesided stretch bonded laminate material.

FIG. 3 illustrates a cross sectional view of another embodiment of asingle sided stretch bonded laminate material.

FIG. 4 illustrates a cross sectional view of yet another embodiment of asingle sided stretch bonded laminate material.

FIG. 5 illustrates a cross sectional view of one embodiment of a doublesided stretch bonded laminate material.

FIG. 6 illustrates an alternative method of manufacturing a single sidedstretch bonded laminate in accordance with the invention.

FIG. 7 illustrates a personal care product utilizing a single sidedstretch bonded laminate made in accordance with the invention.

FIG. 8 illustrates a cross-sectional view of an embodiment of a singlesided stretch bonded laminate with a multi-layer meltblown layer.

DEFINITIONS

Within the context of this specification, each term or phrase below willinclude the following meaning or meanings.

As used herein, the term “personal care product” means diapers, trainingpants, swimwear, absorbent underpants, adult incontinence products, andfeminine hygiene products, such as feminine care pads, napkins andpantiliners. While a diaper is illustrated in FIG. 7, it should berecognized that the inventive material may just as easily beincorporated in any of the previously listed personal care products asan elastic component. For instance, such material may be utilized tomake the elastic side panels of training pants.

As used herein the term “protective outerwear” means garments used forprotection in the workplace, such as surgical gowns, hospital gowns,covergowns, labcoats, masks, and protective coveralls.

As used herein, the terms “protective cover” and “protective outercover”mean covers that are used to protect objects such as for example car,boat and barbeque grill covers, as well as agricultural fabrics.

As used herein, the terms “polymer” and “polymeric” when used withoutdescriptive modifiers, generally include but are not limited to,homopolymers, copolymers, such as for example, block, graft, random andalternating copolymers, terpolymers, etc. and blends and modificationsthereof. Furthermore, unless otherwise specifically limited, the term“polymer” includes all possible spatial configurations of the molecule.These configurations include, but are not limited to isotactic,syndiotactic and random symmetries.

As used herein, the terms “machine direction” or MD means the directionalong the length of a fabric in the direction in which it is produced.The terms “cross machine direction,” “cross directional,” or CD mean thedirection across the width of fabric, i.e. a direction generallyperpendicular to the MD.

As used herein, the term “nonwoven web” means a polymeric web having astructure of individual fibers or threads which are interlaid, but notin an identifiable, repeating manner. Nonwoven webs have been, in thepast, formed by a variety of processes such as, for example, meltblowingprocesses, spunbonding processes, hydroentangling, air-laid and bondedcarded web processes.

As used herein, the term “bonded carded webs” refers to webs that aremade from staple fibers which are usually purchased in bales. The balesare placed in a fiberizing unit/picker which separates the fibers. Next,the fibers are sent through a combining or carding unit which furtherbreaks apart and aligns the staple fibers in the machine direction so asto form a machine direction-oriented fibrous nonwoven web. Once the webhas been formed, it is then bonded by one or more of several bondingmethods. One bonding method is powder bonding wherein a powderedadhesive is distributed throughout the web and then activated, usuallyby heating the web and adhesive with hot air. Another bonding method ispattern bonding wherein heated calender rolls or ultrasonic bondingequipment is used to bond the fibers together, usually in a localizedbond pattern through the web and/or alternatively the web may be bondedacross its entire surface if so desired. When using bicomponent staplefibers, through-air bonding equipment is, for many applications,especially advantageous.

As used herein the term “spunbond” refers to small diameter fibers whichare formed by extruding molten thermoplastic material as filaments froma plurality of fine, usually circular capillaries of a spinneret withthe diameter of the extruded filaments being rapidly reduced as by meansshown, for example in U.S. Pat. No. 4,340,563 to Appel et al., and U.S.Pat. No. 3,692,618 to Dorschner et al., U.S. Pat. No. 3,802,817 toMatsuki et al., U.S. Pat. No. 3,338,992 and U.S. Pat. No. 3,341,394 toKinney, U.S. Pat. No. 3,542,615 to Dobo et al., each of which isincorporated by reference in its entirety herein.

As used herein, the term “meltblown” means fibers formed by extruding amolten thermoplastic material through a plurality of fine, usuallycircular die capillaries as molten threads or filaments into converginghigh velocity gas (e.g. air) streams which attenuate the filaments ofmolten thermoplastic material to reduce their diameter, which may be tomicrofiber diameter. Thereafter, the meltblown fibers are carried by thehigh velocity gas stream and are deposited on a collecting surface toform a web of randomly dispersed meltblown fibers. Such a process isdisclosed, in various patents and publications, including NRL Report4364, “Manufacture of Super-Fine Organic Fibers” by B. A. Wendt, E. L.Boone and D. D. Fluharty; NRL Report 5265, “An Improved Device For TheFormation of Super-Fine Thermoplastic Fibers” by K. D. Lawrence, R. T.Lukas, J. A. Young; and U.S. Pat. No. 3,849,241, issued Nov. 19, 1974,to Butin, et al. incorporated by reference herein in its entirety.

As used herein, the terms “sheet” and “sheet material” shall beinterchangeable and in the absence of a word modifier, refer to wovenmaterials, nonwoven webs, polymeric films, polymeric scrim-likematerials, and polymeric foam sheeting.

The basis weight of nonwoven fabrics or films is usually expressed inounces of material per square yard (osy) or grams per square meter (g/m²or gsm) and the fiber diameters are usually expressed in microns. (Notethat to convert from osy to gsm, multiply osy by 33.91). Filmthicknesses may also be expressed in microns or mil.

As used herein, the term “laminate” refers to a composite structure oftwo or more sheet material layers that have been adhered through abonding step, such as through adhesive bonding, thermal bonding, pointbonding, pressure bonding, extrusion coating or ultrasonic bonding.

As used herein, the term “elastomeric” shall be interchangeable with theterm “elastic” and refers to sheet material which, upon application of astretching force, is stretchable in at least one direction (such as theCD direction), and which upon release of the stretching forcecontracts/returns to approximately its original dimension. For example,a stretched material having a stretched length which is at least 50percent greater than its relaxed unstretched length, and which willrecover to within at least 50 percent of its stretched length uponrelease of the stretching force. A hypothetical example would be a one(1) inch sample of a material which is stretchable to at least 1.50inches and which, upon release of the stretching force, will recover toa length of not more than 1.25 inches. Desirably, such elastomeric sheetcontracts or recovers up to 50 percent of the stretch length in aparticular direction, such as in either the machine direction or thecross machine direction. Even more desirably, such elastomeric sheetmaterial recovers up to 80 percent of the stretch length in a particulardirection, such as in either the machine direction or the cross machinedirection. Even more desirably, such elastomeric sheet material recoversgreater than 80 percent of the stretch length in a particular direction,such as in either the machine direction or the cross machine direction.Desirably, such elastomeric sheet is stretchable and recoverable in boththe MD and CD directions.

As used herein, the term “semi-elastic” refers to sheet material thatmay be elastic or elastomeric, or that may be stretchable in at leastone direction (such as the CD direction) and upon release of thestretching force at least partially retracts. For example, when asemi-elastic material is stretched to 200% its original dimension, uponrelease of the stretching force, the semi-elastic material will retractto less than 200% its original dimension, such as less than 175% itsoriginal dimension, or less than 150% its original dimension.

As used herein, the term “elastomer” shall refer to a polymer which iselastomeric.

As used herein, the term “thermoplastic” shall refer to a polymer whichis capable of being melt processed.

As used herein, the term “inelastic” or “nonelastic” refers to anymaterial which does not fall within the definition of “elastic” above.

As used herein, the term “multilayer laminate” means a laminateincluding a variety of different sheet materials. For instance, amultilayer laminate may include some layers of spunbond and somemeltblown such as a spunbond/meltblown/spunbond (SMS) laminate andothers as disclosed in U.S. Pat. No. 4,041,203 to Brock et al., U.S.Pat. No. 5,169,706 to Collier, et al., U.S. Pat. No. 5,145,727 to Pottset al., U.S. Pat. No. 5,178,931 to Perkins et al., and U.S. Pat. No.5,188,885 to Timmons et al., each incorporated by reference herein inits entirety. Such a laminate may be made by sequentially depositingonto a moving forming belt first a spunbond fabric layer, then ameltblown fabric layer and last another spunbond layer and then bondingthe laminate, such as by thermal point bonding. Alternatively, thefabric layers may be made individually, collected in rolls, and combinedin a separate bonding step or steps. Multilayer laminates may also havevarious numbers of meltblown layers or multiple spunbond layers in manydifferent configurations and may include other materials like films (F)or coform materials, e.g. SMMS, SM, SFS.

As used herein, the term “coform” means a process in which at least onemeltblown diehead is arranged near a chute through which other materialsare added to the web while it is forming. Such other materials may bepulp, superabsorbent particles, cellulose or staple fibers, for example.Coform processes are shown in U.S. Pat. No. 4,818,464 to Lau and U.S.Pat. No. 4,100,324 to Anderson et al., each incorporated by referenceherein in its entirety.

As used herein, the term “conjugate fibers” refers to fibers which havebeen formed from at least two polymers extruded from separate extrudersbut spun together to form one fiber. Conjugate fibers are also sometimesreferred to as multicomponent or bicomponent fibers. The polymers areusually different from each other though conjugate fibers may bemonocomponent fibers. The polymers are arranged in substantiallyconstantly positioned distinct zones across the cross-section of theconjugate fibers and extend continuously along the length of theconjugate fibers. The configuration of such conjugate fiber may be, forexample, a sheath/core arrangement wherein one polymer is surrounded byanother or may be a side-by-side arrangement, a pie arrangement or an“islands-in-the-sea” arrangement. Conjugate fibers are taught in U.S.Pat. No. 5,108,820 to Kaneko et al., U.S. Pat. No. 4,795,668 to Kruegeret al., and U.S. Pat. No. 5,336,552 to Strack et al. Conjugate fibersare also taught in U.S. Pat. No. 5,382,400 to Pike et al., and may beused to produce crimp in the fibers by using the differential rates ofexpansion and contraction of the two or more polymers. For two componentfibers, the polymers may be present in varying desired ratios. Thefibers may also have shapes such as those described in U.S. Pat. No.5,277,976 to Hogle et al., U.S. Pat. No. 5,466,410 to Hills and U.S.Pat. No. 5,069,970 and U.S. Pat. No. 5,057,368 to Largman et al., whichdescribe fibers with unconventional shapes. Each of the foregoingpatents is incorporated by reference herein in its entirety.

As used herein the term “thermal point bonding” involves passing afabric or web of fibers to be bonded between a heated calender roll andan anvil roll. The calender roll is usually, though not always,patterned in some way so that the entire fabric is not bonded across itsentire surface, and the anvil roll is usually flat. As a result, variouspatterns for calender rolls have been developed for finctional as wellas aesthetic reasons. One example of a pattern has points and is theHansen Pennings or “H&P” pattern with about a 30 percent bond area withabout 200 bonds/square inch as taught in U.S. Pat. No. 3,855,046 toHansen and Pennings, incorporated herein by reference in its entirety.The H&P pattern has square point or pin bonding areas wherein each pinhas a side dimension of 0.038 inches (0.965 mm), a spacing of 0.070inches (1.778 mm) between pins, and a depth of bonding of 0.023 inches(0.584 mm). The resulting pattern has a bonded area of about 29.5percent. Another typical point bonding pattern is the expanded HansenPennings or “EHP” bond pattern which produces a 15 percent bond areawith a square pin having a side dimension of 0.037 inches (0.94 mm), apin spacing of 0.097 inches (2.464 mm) and a depth of 0.039 inches(0.991 mm). Another typical point bonding pattern designated “714” hassquare pin bonding areas wherein each pin has a side dimension of 0.023inches, a spacing of 0.062 inches (1.575 mm) between pins, and a depthof bonding of 0.033 inches (0.838 mm). The resulting pattern has abonded area of about 15 percent. Yet another common pattern is theC-Star pattern which has a bond area of about 16.9 percent. The C-Starpattern has a cross-directional bar or “corduroy” design interrupted byshooting stars. Other common patterns include a diamond pattern withrepeating and slightly offset diamonds with about a 16 percent bond areaand a wire weave pattern looking as the name suggests, e.g. like awindow screen pattern having a bond area in the range of from about 15percent to about 21 percent and about 302 bonds per square inch.

Typically, the percent bonding area varies from around 10 percent toaround 30 percent of the area of the fabric laminate. As is well knownin the art, the spot bonding holds the laminate layers together as wellas imparts integrity to each individual layer by bonding filamentsand/or fibers within each layer.

As used herein, the term “ultrasonic bonding” means a process performed,for example, by passing the fabric between a sonic horn and anvil rollas illustrated in U.S. Pat. No. 4,374,888 to Bornslaeger, incorporatedby reference herein in its entirety.

As used herein, the term “adhesive bonding” means a bonding processwhich forms a bond by application of an adhesive. Such application ofadhesive may be by various processes such as slot coating, spray coatingand other topical applications. Further, such adhesive may be appliedwithin a product component and then exposed to pressure such thatcontact of a second product component with the adhesive containingproduct component forms an adhesive bond between the two components.

As used herein, the term “post-calender treatment” refers to anytreatment, such as the application of a nonblocking agent, that istypically applied to a laminate toward the end of the laminationprocess, such as following the passage of the laminate through a nip orover a calender roll, in order to reduce inter-layer peel strength.

As used herein, the term “inter-layer peel strength” refers to the peelstrength required to separate a laminate from itself when unwound from aroll, as opposed to the peel strength between layers within thelaminate. Inter-layer peel strength can be determined using the RollBlocking Test Method described in detail below.

As used herein, and in the claims, the term “comprising” is inclusive oropen-ended and does not exclude additional unrecited elements,compositional components, or method steps. Accordingly, such term isintended to be synonymous with the words “has”, “have”, “having”,“includes”, “including”, and any derivatives of these words.

As used herein, the terms “extensible” or “expandable” mean elongatablein at least one direction, but not necessarily recoverable.

Unless otherwise indicated, percentages of components in formulationsare by weight.

DETAILED DESCRIPTION OF THE INVENTION

For the purposes of this invention an elastic single sided stretchbonded laminate includes at least one elastic layer and one gatherablefacing layer, the gatherable facing layer being applied to only one sideof at least one elastic layer. The elastic layer suitably includes anarray of continuous filament strands with a meltblown layer deposited onthe continuous filament strands. The laminate suitably includes anelastic polyolefin-based polymer having a degree of crystallinitybetween about 3% and about 40%, or between about 5% and about 30%, orbetween about 15% and about 25%. The elastic polyolefin-based polymermay also have a melt flow rate between about 10 and about 600 grams per10 minutes, or between about 60 and about 300 grams per 10 minutes, orbetween about 150 and about 200 grams per 10 minutes; amelting/softening point between about 40 and about 160 degrees Celsius;and/or a density from about 0.8 to about 0.95, or about 0.85 to about0.93, or about 0.86 to about 0.89 grams per cubic centimeter. Theelastic polyolefin-based polymer may include polyethylene,polypropylene, butene, or octene homo- or copolymers, ethylenemethacrylate, ethylene vinyl acetate, butyl acrylate copolymers, or acombination of any of these polymers.

One example of a suitable elastic polyolefin-based polymer is VISTAMAXX,available from ExxonMobil Chemical of Baytown, Tex. Other examples ofsuitable polyolefin-based polymers include EXACT plastomer, OPTEMAethylene methacrylate, and VISTANEX polyisobutylene, andmetallocene-catalyzed polyethylene, all available from ExxonMobilChemical, as well as AFFINITY polyolefin plastomers, such as AFFINITYEG8185 or AFFINITY GA1950, available from Dow Chemical Company ofMidland, Mich.; ELVAX ethylene vinyl acetate, available from E. I. DuPont de Nemours and Company of Wilmington, Del.; and ESCORENE Ultraethylene vinyl acetate, available from ExxonMobil.

The elastic polyolefin-based polymer suitably has a slow crystallizationrate, with partial regions of crystalline and amorphous phases that makeit inherently elastic and tacky. The elastic polyolefin-based polymermay be incorporated within the meltblown layer, the continuous filamentstrands, and/or the facing layer, as described in greater detail below.

It is desirable that such single-sided stretch bonded laminate materialdemonstrate a stretch to stop value of between about 30 and 400 percent.In an alternative embodiment, such material demonstrates a stretch tostop value of between about 50 and 300 percent. In still a furtheralternative embodiment, such laminate material demonstrates a stretch tostop value of between about 80 and 250 percent.

As mentioned, the elastic layer suitably includes an array of continuousfilament strands with a meltblown layer deposited on the continuousfilament strands. Additional components may be included in the elasticlayer, such as a film, an elastic scrim or netting structure, a foammaterial, or a combination of any of the foregoing materials. If a filmis used, it may be an apertured film. In certain embodiments, any ofthese additional components may be used in place of the array ofcontinuous filament strands and/or the meltblown layer. The combinationof a generally parallel series of elastomeric continuous filaments orstrands (fiber array) and meltblown materials deposited on the filamentsis described in previously noted U.S. Pat. No. 5,385,775 to Wright. Thefilament to meltblown basis weight ratio in such an elastic layer may beabout 90:10, for example.

At least one of the components of the elastic layer may be formed froman elastic polyolefin-based polymer having a degree of crystallinitybetween about 3% and about 40%, or between about 5% and about 30%, orbetween about 15% and about 25%, as described above. When the elasticpolymer is used to form the meltblown layer, for example, the slowcrystallization rate of the elastic polymer is advantageous because themeltblown fibers are semi-tacky as they are deposited on the formingwire, which keeps the elastic strands in place and adhesively bonds thecomposite. Additionally, when the meltblown layer includes the elasticpolymer, the meltblown layer may be applied at a higher add-on comparedto non-elastic meltblown layers. More particularly, the elasticmeltblown layer may be applied at an add-on up to about 34 gsm, orbetween about 1 and about 5 grams per square meter (gsm), or betweenabout 1.25 and about 2.5 gsm, as measured when the layer is fullyextended. Inelastic meltblown tends to crack and form discrete islandsas the strands stretch prior to lamination at higher add-on levels,which leads to non-uniformity. However, elastic meltblown does notsuffer such drawbacks at higher add-on levels. Furthermore, the higheradd-on of elastic meltblown coupled with the tackiness of the elasticmeltblown helps to better secure the filaments to the facing layer suchthat the filaments are less likely to come loose, as demonstrated byinter-layer peel strength that is greater than intra-layer peelstrength. More particularly, the peel strength of the layers within thelaminate is greater than the peel strength of the exterior surfaces ofthe layers to one another when the laminate is unwound from a roll. Forinstance, the laminate may have an intra-layer peel strength of about200 to about 450 grams per 3 inches cross-directional width at a strainrate of 300 mm/min, using the same test method as used for determiningthe inter-layer peel strength but instead pulling apart the elasticlayer from the facing layer. The higher add-on of elastic meltblown mayalso help reduce porosity.

Another benefit of using the elastic polyolefin-based polymer in themeltblown layer is the reduction or elimination of roll blocking, asdemonstrated through the low inter-layer peel strength of the laminate.Other laminates may include post-calender treatment, such as non-elasticpolypropylene meltblown dusting, to prevent roll blocking, but theincorporation of the elastic polymer in the meltblown layer may removethe need for any post-calender treatment. Incorporation of the elasticmeltblown layer without any post-calender treatment may result in aninter-layer peel strength of the laminate of less than about 70 gramsper 3 inches cross-directional width at a strain rate of 300 mm/min, orless than about 60 grams per 3 inches cross-directional width at astrain rate of 300 mm/min, or less than about 50 grams per 3 inchescross-directional width at a strain rate of 300 mm/min. A shorter widthof laminate may provide non-uniform results, but for the most part theinter-layer peel strength of the laminate has a linear relationship withrespect to the width of the laminate. Thus, for example, a laminatehaving a width of 3 inches may exhibit inter-layer peel strength ofabout 60 grams per 3 inches cross-directional width at a strain rate of300 mm/min, while the same laminate having a width of 1 inch may exhibitinter-layer peel strength of about 20 grams per inch cross-directionalwidth at a strain rate of 300 mm/min.

The meltblown layer may include, for example, between about 30% andabout 100%, or between about 50% and about 80%, by weight elasticpolyolefin-based polymer. The meltblown layer may be a single layer or amulti-layer component, as shown in FIG. 8. For example, the meltblownlayer may include a layer of an elastic polyolefin-based meltblownpolymer 90 having a degree of crystallinity between about 3% and about40% and the meltblown layer may also include a layer of styrenic blockcopolymer-based meltblown polymer 91, as described in greater detailbelow.

As mentioned, the continuous filament strands may also include anelastic polyolefin-based polymer. More particularly, the continuousfilament strands may be composed of between about 5% and about 90%, orbetween about 30% and about 70%, by weight elastic polyolefin-basedpolymer.

Furthermore, any or all of the components within the elastic layer(whether the meltblown layer, the filaments, or other components) mayinclude thermoplastic materials such as block copolymers having thegeneral formula A-B-A′ where A and A′ are each a thermoplastic polymerendblock which contains a styrenic moiety such as a poly (vinyl arene)and where B is an elastomeric polymer midblock such as a conjugateddiene or a lower alkene polymer.

Specific examples of useful styrenic block copolymers includehydrogenated polyisoprene polymers such asstyrene-ethylenepropylene-styrene (SEPS),styrene-ethylenepropylene-styrene-ethylenepropylene (SEPSEP),hydrogenated polybutadiene polymers such asstyrene-ethylenebutylene-styrene (SEBS),styrene-ethylenebutylene-styrene-ethylenebutylene (SEBSEB),styrene-butadiene-styrene (SBS), styrene-isoprene-styrene (SIS), andhydrogenated poly-isoprene/butadiene polymer such asstyrene-ethylene-ethylenepropylene-styrene (SEEPS). Polymer blockconfigurations such as diblock, triblock, multiblock, star and radialare also contemplated in this invention. In some instances, highermolecular weight block copolymers may be desirable. Block copolymers areavailable from Kraton Polymers U.S. LLC of Houston, Tex. under thedesignations Kraton G or D polymers, for example G1652, G1657, G1730,D1114, D1155, D1102 and Septon Company of America, Pasadena, Tex. underthe designations Septon 2004, Septon 4030, and Septon 4033. Otherpotential suppliers of such polymers include Dexco Polymers of Tex. andDynasol of Spain. Blends of such elastomeric resin materials are alsocontemplated as the primary component of the elastic layer.Additionally, other desirable block copolymers are disclosed in U.S.Patent Publication 2003/0232928A1 which is incorporated by referenceherein in its entirety.

Such base resins may be further combined with tackifiers and/orprocessing aids in compounds. Exemplary compounds include but are notlimited to KRATON G 2760, and KRATON G 2755. Processing aids that may beadded to the elastomeric polymer described above include a polyolefin toimprove the processability of the composition. The polyolefin must beone which, when so blended and subjected to an appropriate combinationof elevated pressure and elevated temperature conditions, is extrudable,in blended form, with the elastomeric base polymer. Useful blendingpolyolefin materials include, for example, polyethylene, polypropyleneand polybutene, including ethylene copolymers, propylene copolymers andbutene copolymers. A particularly useful polyethylene may be obtainedfrom Eastman Chemical under the designation EPOLENE C-10. Two or more ofthe polyolefins may also be utilized. Extrudable blends of elastomericpolymers and polyolefins are disclosed in, for example, U.S. Pat. No4,663,220.

The elastomeric filaments may have some tackiness/adhesiveness toenhance autogenous bonding. For example, the elastomeric polymer itselfmay be tacky when formed into films, and/or filaments or, alternatively,a compatible tackifying resin may be added to the extrudable elastomericcompositions described above to provide tackified elastomeric fibersand/or filaments that autogenously bond. In regards to the tackifyingresins and tackified extrudable elastomeric compositions, note theresins and compositions as disclosed in U.S. Pat. No.4,787,699, herebyincorporated by reference in its entirety.

Any tackifier resin can be used which is compatible with the elastomericpolymer and can withstand the high processing (e.g. extrusion)temperatures. If the elastomeric polymer (e.g. A-B-A elastomeric blockcopolymer) is blended with processing aids such as, for example,polyolefins or extending oils, the tackifier resin should also becompatible with those processing aids. Generally, hydrogenatedhydrocarbon resins are preferred tackifying resins, because of theirbetter temperature stability. REGALREZ series tackifiers are examples ofsuch hydrogenated hydrocarbon resins. REGALREZ hydrocarbon resins areavailable from Eastman Chemical. Of course, the present invention is notlimited to use of such tackifying resins, and other tackifying resinswhich are compatible with the other components of the composition andcan withstand the high processing temperatures, can also be used. Othertackifiers are available from ExxonMobil under the ESCOREZ designation.

Other exemplary elastomeric materials which may be used includepolyurethane elastomeric materials such as, for example, those availableunder the trademark ESTANE from Noveon, polyamide elastomeric materialssuch as, for example, those available under the trademark PEBAX(polyether amide) from Ato Fina Company, and polyester elastomericmaterials such as, for example, those available under the tradedesignation HYTREL from E. I. DuPont De Nemours & Company.

Useful elastomeric polymers also include, for example, elastic polymersand copolymers of ethylene and at least one vinyl monomer such as, forexample, vinyl acetates, unsaturated aliphatic monocarboxylic acids, andesters of such monocarboxylic acids. The elastic copolymers andformation of elastomeric meltblown fibers from those elastic copolymersare disclosed in, for example, U.S. Pat. No. 4,803,117, incorporated byreference herein in its entirety.

Additional materials which may be utilized in the elastic layer toprovide some extensibility with limited recovery, include single sitecatalyzed polyolefinic materials, such as metallocene catalyzedpolyolefins and constrained geometry polyolefins, as available from Dowunder the designation AFFINITY and from ExxonMobil, under thedesignation EXACT. Desirably, such materials have densities of less than0.89 g/cc.

Finally, pre-formed elastic strands are also contemplated to be withinthe scope of this invention. Such preformed strands, such as solutiontreated materials, include LYCRA from Dupont and GLOSPAN, available fromGLOBE. This material may serve as the basis for a continuous filamentarray component (elastic layer) of a stretch bonded laminate material,or alternatively a film component of a stretch bonded laminate.

Typically, the blend used to form the web, film or filaments when suchis made from an extruded material in an on-line process, includes forexample, from about 40 to about 90 percent by weight elastomeric polymerbase resin, from about 0 to about 40 percent polyolefin processing aid,and from about 5 to about 40 percent resin tackifier. These ratios canbe varied depending on the specific properties desired and the polymersutilized. For an alternative embodiment, such blend includes betweenabout 60 and 80 percent base resin, between about 5 to 30 percentprocessing aid, and between about 10 and 30 percent tackifier. In afurther alternative embodiment, such blend includes a tackifier in anamount of between about 10 and 20 percent tackifier.

In embodiments in which the meltblown layer does not include the elasticpolyolefin-based polymer, a nonblocking agent may be applied to theelastic layer either as a nonblocking agent layer on a side opposite tothat of the facing layer, or as a bonding agent (adhesive) between theelastic layer and the gatherable facing layer, or alternatively, as abonding agent between the elastic layer and the gatherable facing layerand additionally over the bonded laminate, on a side opposite to that ofthe facing layer.

The gatherable facing layer gathers between points on its surface thatare bonded to the elastic layer. Essentially, those areas that aregathered are not bonded to the elastic layer. While it is desirable thatthe gatherable layer be a nonwoven layer, such gatherable layer may alsobe a woven web, a cellulosic web as will later be described, a metallicfoil-type layer or a combination of such. Such gatherable material mayalso be pretreated in some fashion prior to being bonded to the elasticlayer. Such pretreatments include for instance being necked. Suchpretreatment may offer additional properties to the overall laminatematerial, such as bi or multidirectional stretch capabilities. Suchgatherable layer may itself include multiple layers, and as such be amultilayered laminate.

The gatherable facing layer may be a nonwoven material such as, forexample, one or more spunbonded webs (such as a conjugate fiber spunbondweb), meltblown webs, or bonded carded webs. An example of a spunbondweb may be a polypropylene spunbond web having a basis weight of betweenabout 0.3 and 0.8 osy. In a further alternative embodiment, the spunbondweb is necked between about 25 and 60 percent before it is bonded to theelastic layer. In still a further embodiment of the invention, thegatherable layer is a multilayer material having, for example, at leastone layer of spunbond web joined to at least one layer of meltblown web,bonded carded web, or other suitable material. The gatherable layer mayalso be a composite material made of a mixture of two or more differentfibers or a mixture of fibers and particulates, such as a coformmaterial. Such mixtures may be formed by adding fibers and/orparticulates to the gas stream in which meltblown fibers are carried sothat an intimate entangled comingling of meltblown fibers and othermaterials, i.e. woodpulp, staplefibers and particulates such as, forexample, hydrocolloid (hydrogel), particulates commonly referred to assuperabsorbent materials, occurs prior to collection of the meltblownfibers upon a collecting device to form a coherent web of randomlydispersed meltblown fibers and other materials such as disclosed in U.S.Pat. No. 4,100,324, the disclosure of which is hereby incorporated byreference in its entirety. The facing layer may either be unwound from aroll or formed in-line.

As mentioned, the facing layer may also include an elasticpolyolefin-based polymer, as described above. More particularly, thefacing layer may be composed of between about 0% and about 100%, orbetween about 60% and about 100%, by weight elastic polyolefin-basedpolymer. In certain embodiments, for example, the facing layer may be aspunbond-meltblown-spunbond laminate in which the meltblown layerincludes, in whole or in part, the -elastic polyolefin-based polymer.Alternatively, the facing layer may be spunbond, meltblown,hydroentangled, or other type of nonwoven material including the elasticpolyolefin-based polymer. In certain embodiments, for example, both thefacing layer and the elastic meltblown layer may include an elasticpolyolefin-based polymer, as described above. In such embodiments, thelaminate does not include any conventional facing layers per se, butinstead may include two layers of the elastic polyolefin-based polymerpositioned on opposite sides of the array of continuous filamentstrands. More particularly, as illustrated in FIG. 2, both the facinglayer 85 and the meltblown layer 89 may include the elasticpolyolefin-based polymer.

The gatherable layer may be made of pulp fibers, including wood pulpfibers, to form a material such as, for example, a tissue layer.Additionally, the gatherable layer may be a layer or layers ofhydraulically entangled fibers such as, for example hydraulicallyentangled mixtures of wood pulp and staple fibers such as disclosed, forexample, in U.S. Pat. No. 4,781,966, the disclosure of which is herebyincorporated by reference in its entirety.

The single sided stretch bonded laminate is desirably made using one ofthree methods. In particular, the material may be made using either anextrusion and bonding method with an elastic polyolefin-based meltblownlayer having a slow rate of crystallization, or an extrusion and bondingmethod with a meltblown nonblocking agent treatment thereon (to form anonblocking agent layer), an application of a pre-bonding adhesive thathas a relatively low open time and becomes non-tacky followingapplication, or an application of a pre-bonding adhesive that has arelatively low open time and a post-bonding application of such anadhesive, with the adhesive becoming non-tacky following application.The various methods may be described in one embodiment as involving abonding agent, even though all of the methods do not involve “adhesives”per se. The methods can be variously characterized as involvingmechanical entanglement which, in effect, mechanically bonds layerstogether without a tacky result.

The attributes of a semi-tacky elastic polyolefin-based meltblown layerhaving a slow rate of crystallization are described above. Moreparticularly, the meltblown fibers are semi-tacky when deposited on theforming wire, which keeps the elastic strands in place and adhesivelybonds the laminate. Additionally, the elastic meltblown layer can beapplied at a relatively high add-on, which contributes to the bondingbetween the facing layer and the filaments.

In embodiments including a nonblocking agent, the nonblocking agenttreatment may include application of a relatively low basis weightmeltblown material, such that no readily visible (with the human eye)web is formed, to the top of tacky elastic layers within the laminate.Such nonblocking agent treatment is desirably a dusting of meltblown,such as between about 0.2 and 2.0 gsm of meltblown materials. In analternative embodiment, such meltblown application is between about 0.2and 1.5 gsm of meltblown materials. In still another alternativeembodiment, such meltblown application is between about 0.2 and 0.8 gsm.In yet another alternative embodiment, such meltblown application isbetween about 0.2 and 0.5 gsm. The basis weight of the meltblownmaterials is determined at the point of lamination. Depending on whatattributes are desired, the meltblown application is varied within theserespective ranges. For instance, if a more elastic laminate is desired,the meltblown application would necessarily be on the lower end of therange. Desirably, such meltblown is a non-tacky polypropylene meltblownmaterial which is exemplified by VALTEC HH442H (having a MFR of 1100 at230° C./2.16 kg of ASTM D1238) by Basell, and Basell PF-015. Suchmeltblown material may be produced by one or more meltblown banksdepending on the basis weight desired. Alternatively, such meltblown maybe of an elastic material without tackifier.

If an adhesive method is used to create such single sided facing stretchbonded laminate, it is desirable that such adhesive have a relativelyshort open time of between about 0.2 seconds (sec) and 1 minute. In analternative embodiment, such open time is between about 0.2 sec and 3seconds. In still a further alternative embodiment, such open time isbetween about 0.5 sec and 2 seconds. An exemplary adhesive with suchproperties is a polypropylene-based hot melt adhesive (that becomesnontacky shortly after application, upon solidification) consisting ofup to 65 percent or between about 15-40 percent atactic polypropylene,in one embodiment about 50 weight percent Huntsman H2115 (atacticpolypropylene from Huntsman Polymers); between about 20-50 percenttackifier, in one embodiment about 30 percent ExxonMobil ESCOREZ 5300;between about 2-10 percent styrenic block copolymer, in one embodimentabout 4 percent SEPTON 2002 of Septon Polymers; between about 10-20percent isotactic polypropylene, in one embodiment, about 16 percent PP3746G (isotactic polypropylene) also of ExxonMobil; between about 0-2percent coloring agent, in one embodiment about 2 percent of a coloringagent, such as 50 percent titanium dioxide in VECTOR 4411 and finally;between about 0.2-1 percent stabilizer, in one embodiment, about 0.5percent IRGANOX 1010 from Ciba Specialty Chemicals. It should beappreciated that the various components may have other substitutes, suchas stabilizers other than IRGANOX. Furthermore, it should be appreciatedthat such adhesives may also not contain coloring agents, depending onproduct application. Other adhesives may be used with the presentinvention including those derived from the adhesives described in U.S.Pat. Nos. 6,657,009 and 6,774,069, U.S. application Ser. Nos.09/945,239, 09/945,240, 10/655,717, and U.S. Publication Nos.US20020122953, US20020123726, each of which is incorporated herein byreference in its entirety.

In one embodiment, it is desirable that the adhesive be applied in apre-bonding step (that is prior to (such as immediately prior to)bringing the elastic layer and the single facing layer together in anip) at a basis weight of less than about 16 gsm. In an alternativeembodiment, such adhesive is applied at a basis weight of less thanabout 8 gsm. In still a further alternative embodiment, it is desirablethat such adhesive be applied at a basis weight of less than about 4gsm. In still a further alternative embodiment, it is desirable that theadhesive be applied at between 1 and 4 gsm. In one embodiment, it isdesirable that such adhesive be applied by spray, such as throughsystems available from ITW or other such spray applications. Such sprayapplication is in one embodiment sprayed onto one of the layers, such ason the facing layer or the meltblown layer. In an alternativeembodiment, such spray is into the nip at which the facing and elasticlayers are joined, or at which the meltblown layer and the filaments arejoined.

If the adhesive is to be applied as a pre-bonding and postbonding step(prebonding as previously described), it is desirable that the adhesivebe applied on the materials (as will be described below) in an amount ofless than 4 gsm prior to bonding of the various layers. In analternative embodiment, such adhesive is desirably applied in an amountof less than 2 gsm prior to bonding of the various layers. In stillanother alternative embodiment, such adhesive is applied in a prebondingstep in a range of between about 1 and 4 gsm and in a post bonding stepof between about 0-4 gsm. In still a further alternative embodiment,such adhesive is applied in a prebonding and post bonding method at atotal of between about 6 and 8 gsm. The term postbonding refers to apost-calender treatment and, more specifically, shall mean applicationof the adhesive or nonblocking agent following exiting of the bondedelastic layer and facing layer from a nip, and before winding on a rollfor storage. For example, application of the postbonding adhesive ornonblocking agent can be to a side of the elastic layer/facing layerlaminate opposite to the facing layer.

In one embodiment, a method for producing a single sided facing stretchbonded elastic laminate material utilizes a facing such as that whichhas been previously described, and an array of continuous elasticfilaments bonded to the facing through the application of the elasticmeltblown layer, such that the laminate has a structure of ABC, in whichthe “A” represents the single side facing, the “B” represents theelastic meltblown layer, and the “C” represents the continuous elasticfilaments. Alternatively, the “B” may represent the continuous elasticfilaments and the “C” may represent the elastic meltblown layer. In sucha fashion the resulting material demonstrates increased stretch levels,and the ability of the material to be rolled for storage over itself ifit is not to be used immediately. The material likewise demonstratesenhanced gathering of the single facing since the stretch bondedlaminate is allowed to retract to a greater extent than would bepossible with two opposing facing layers attached.

As can be seen in FIG. 1, which illustrates a schematic view of a methodfor manufacturing a single sided stretch bonded laminate material inaccordance with the invention, FIG. 1 illustrates a horizontal,continuous filament laminate manufacturing process 10. A first extrusionapparatus 20 is fed with a polymer blend composition from one or moresources (not shown) which is extruded onto a forming surface 30 infilament form 31. The extruded polymer is desirably a styrenic blockcopolymer elastomer and/or an elastic polyolefin-based polymer. Invarious embodiments, the extrusion apparatus 20, or a second extrusionapparatus 35, can be configured to produce other materials, e.g.thermoplastic fibers 36, to achieve the inline placement of layers ofthe same or different materials. Techniques for fiber extrusion, such asmodified meltblowing of the fibers, are further set forth in thepreviously mentioned U.S. Pat. No. 5,385,775 to Wright. Apparatus 20extrudes filaments 31 directly onto a conveyor system, which can be aforming surface system 30 (e.g., a foraminous belt) moving clockwiseabout rollers 40. A vacuum (not shown) can also help hold the filaments31 against the foraminous wire system. A meltblown layer, also of anelastomeric material such as the materials previously described,particularly an elastic polyolefin-based polymer, is extruded fromadjacent bank 45, such that the meltblown fibers 46 are placed on top ofthe continuous filaments 31 (array). The meltblown material is in oneembodiment applied such that it represents 10 basis weight percent ofthe filament and meltblown structure, for example. In a particularembodiment, the elastic polyolefin-based polymer composition is the samein both the filaments and meltblown materials. In an alternativeembodiment, the compositions are different (which may include the samebase resin, but different percentages of processing aid or tackifiers).

In certain embodiments, particularly those wherein the meltblown layerdoes not include an elastic polyolefin-based polymer, one or moreadditional meltblown banks (not shown) may be positioned downstream andadjacent the first meltblown bank to extrude a nonblocking agent ontothe top of the extruded elastic meltblown layer(s). Such a nonblockingagent may be a polyolefin or elastic polyolefin polymer as previouslydescribed. Additionally, amorphous polyalpha olefins (APAO) that are nontacky may be utilized. Additionally, elastomeric materials withouttackifiers may also be utilized. In a further alternative embodimentpolypropylene adhesives such as previously described may likewise bemeltblown on top of the previous elastic meltblown material. In meltingthe materials, a grid melter (typical hot melt equipment) may be used tomelt/provide inorganic or organic drums, pellets, or blocks ofnonblocking agent.

The filament/meltblown laminate may be stretched by the differentialspeed of tensioning rollers (nip rolls) 60 to elongate and tension thefilaments 56. Optionally, the laminate may be compacted, and tensioned,by an additional pair of rolls (not shown). The tension rollers aretherefore operating at speeds which exceed the speed at which themeltblown covered filament array is exiting the forming surface.Desirably the tension rollers 60 are provided with a surface havinglittle to no affinity for the filaments or fibers. In one embodiment,the filaments are stretched between about 3 and 6× from the formingsurface to the tensioning rollers.

At the same time, a single facing layer 67 is either made in line orunwound from a roll 65 and introduced into the set of nip rolls 60 withthe filament array laminate such that the facing layer 67 faces thefilament array side of the laminate, as opposed to the meltblown side ofthe laminate. Alternatively, the single facing layer 67 a may beintroduced into the set of nip rolls 60 with the filament array laminatesuch that the facing layer 67 a faces the meltblown side of thelaminate, as opposed to the filament array side of the laminate, asshown in dashed lines in FIG. 1.

The facing is bonded to the elastic layer (meltblown in particular, viapressure in the nip) while the elastic layer is still being stretched.Both the filament array and facing then exit the nip 60 as a continuousfilament elastic stretch bonded laminate with a single side facinglayer. The elastic laminate 70 is then allowed to relax, forming gatherstherein between bonding points on the facing layer, and is collected ona collection roll 75 for further use. The collection roll then winds thelaminate, typically at a speed less than that of the nip rolls, such asbetween about 0.50 and 0.75 of the nip roll speeds. The nip rollers 60may be desirably designed to provide a 100 percent bond area through theuse of flat calender rolls or may provide a patterned bond area. Therollers 60 can be heated to a degree below the melting/softening pointsof the various laminate components, or may be ambient, or chilled. As analternative embodiment of the method, all rolls that come into contactwith the non-facing side of the laminate desirably include a non-sticksurface, such as a coating of PTFE (TEFLON), or silicone rubber, releasecoating. Such rolls may further be coated with IMPREGLON coatings ofSouthwest Impreglon, of Houston, Tex., or Stowe-Woodward Silfex siliconerubber coatings of a hardness of 60 Shore A. In an alternativeembodiment of this continuous filament array laminate method, ratherthan extruding continuous filaments, preformed elastic strands such asLYCRA strands may be unwound from a drum and fed into a laminating nipunder tension. In still another embodiment, the facing can be neckedprior to being bonded to the elastic layer. Such necking may be betweenabout 25 and 60 percent.

Such laminate structure can be seen in FIG. 2 which illustrates a crosssectional stylistic view of a laminate 80 made in accordance with theinvention. As can be seen in the figure, the facing 85 may be situatedunder/immediately adjacent the filament array 87. An elastic meltblownlayer 89 is positioned on top of the filament array 87 on a sideopposite to that of the facing layer 85. Alternatively, as illustratedin cross section in FIG. 3, a laminate 80 made in accordance with theinvention may include the facing 85 situated under/immediately adjacentthe elastic meltblown layer 89, with the filament array 87 on top of themeltblown layer 89 on a side opposite to that of the facing layer 85.The thicknesses of the various layers are not to scale, and areexaggerated to illustrate their existence. It should be recognized thatwhile each of the various cross sections of these figures illustrate arelatively flat facing layer material, such nonwoven facing layermaterials are actually gathered between where they are bonded to therespective elastic layers (either the strands, film, or webs), but forstylistic purposes, such web is shown in a relatively flatconfiguration. If desired, such single sided filament laminate may thenbe bonded to additional sheet materials as previously described.

In one embodiment, the continuous filaments in such laminates aredesirably present in an amount between about 7 to 18, or about 8 to 15per cross-directional inch. The basis weight of the meltblown materialfrom the first elastic meltblown bank may be up to about 34 gsm, orbetween about 1 and 5 gsm, at the point of lamination. The basis weightof such facing materials bonded to such filaments is desirably betweenabout 0.3 and 0.8 osy. In one embodiment, the filament and elasticmeltblown materials are stretched between approximately 50 and 800percent by the action of the nip rolls (expressed in a ratio, such asabout 0.16 to 0.18 (forming surface speed/nip roll speed)). In a secondalternative embodiment, the filaments are stretched between about 100and 600 percent by the action of the nip rolls.

As an example of this embodiment of the invention, an ABC structurelaminate may be produced in accordance with the methods of U.S. Pat. No.5,385,775, with a polypropylene spunbond facing having a basis weightbetween about 0.3 and 0.6 osy, but desirably in the range of about 0.35to 0.4 osy. The elastic components B and C, which desirably comprise thefilament array and the elastic meltblown layer, desirably include anelastic polyolefin-based polymer, such as VISTAMAXX available fromExxonMobil. Desirably, such polymeric blend also includes a KRATON Gpolymeric compounded blend such as KRATON G 2760 or KRATON G 2755 in thefilaments, and either the same polymeric blend in the elastic meltblownlayer or a second G polymer blend in the meltblown layer. The filamentsto meltblown weight ratio may be in a 90:10 ratio, or other suitableratio.

In certain embodiments, an extensible or semi-elastic facing layer 85 isbonded to an elastic or semi-elastic film 92 having a basis weight ofabout 50 grams per square meter (gsm) or less, or between about 35 toabout 45 gsm, or between about 38 and about 42 gsm, as illustrated inFIG. 4. The facing layer 85 is lower in extension tension than the film92. Consequently, the laminate 80 displays greater retraction thancomparable laminates having two conventional facing layers. Thissubstantial amount of elastic recovery may be attributable to thereinforcing, material mass, and distribution of the extensible orsemi-elastic facing layer 85. More particularly, because the forcerequired to cause permanent deformation of the facing layer 85 is notexceeded, an increase in recovery force is possible. Furthermore, whenstretched, these laminates perform as a mono-component material insteadof a multi-component constructed laminate.

The extensible or semi-elastic facing layer 85 may include the elasticpolyolefin-based polymer, described in detail above, and may bemeltblown, spunbond, hydroentangled, or any other type of nonwovenmaterial, also described in detail above. Furthermore, the laminate 80may include a second extensible facing layer 94, the same as ordifferent than the first facing layer 85 bonded to a surface of the film92 opposite the first facing layer 85, as illustrated in FIG. 5. Thelaminate 80 may also include a plurality of elastomeric strands, ifdesired. The incorporation of the elastic polyolefin-based polymer intoone or more facing layers aids in the reduction of extension force andpermits the use of a lower basis weight elastic or semi-elastic film.Additionally or alternatively, the film 92 may include an elasticpolyolefin-based polymer. Examples of other suitable film materialsinclude any of the elastomeric polymers described herein, particularlythose described with respect to the elastic layer in previousembodiments, provided the film has a basis weight of about 50 gsm orless, or between about 35 to about 45 gsm, or between about 38 and about42 gsm.

In manufacturing the material for examples, the following conditionswere employed. The first extrusion bank that extruded continuousfilaments, extruded KRATON G2760 at 26 lbs/hr. The stretch-to-stop(rSTS) of the filaments for each sample is indicated in Table 1. Theelastic meltblown bank, which followed the filament bank downstream,extruded either BASELL PF-015 polypropylene/nonblocking agent, orVISTAMAXX 2210 (VM) elastic polyolefin-based polymer available fromExxonMobil, at either a low (2.5 gsm) or high (4.9 gsm) add-on. The wireto calender speed ratio was between 0.17 and 0.19, inclusive. When anadhesive was used, the adhesive add-on was 1.5 gsm at the nip. Themeltblown pounds per inch per hour (PIH) is the rate at which thepolymer was applied in the CD across the width of the filament die, andis indicated in Table 1 for each applicable sample.

The extrusion temperature of the continuous filament extrusion diesystem was between about 440 and 500° F. There was no primary air onthis continuous filament system and the polymer was extruded out ontothe forming wire from the filament die. The extrusion temperature of theelastic meltblown layer that was placed on top of the filaments was 451°F. The primary air in the elastic meltblown bank was between about 0.8and 1 psi at about 475° F. The extrusion temperature of the nonblockingagent meltblown die system was between about 350 and 500° F., with thedie itself having a temperature of about 450° F. The primary air in thatdie was about 0.8 to 1 psi. The facing basis weight, which was apolypropylene spunbond nonwoven, was 0.4 osy. The facing was unwoundnear the stretch zone and laminated with the meltblown and strandcomposite. The materials were calendered in a nip with the calenderrolls yielding a surface temperature of ambient to 70 to 85° F. andunder a pressure of about 250 pounds per linear inch on the roll. Theentire laminate was allowed to retract and wound onto a 3-inch core.

The materials were produced having the composition and manufacturingresults as reflected in Table 1 below. The materials were slabbed off ofeach roll and cut into 4-inch by 6-inch samples and then put in ahydraulic press overnight to simulate forces in the roll. The RollBlocking Test Method, described in detail below, was used at a 180degree angle at room temperature to determine inter-layer peel strengthand to quantify blocking potential. One sample of each laminate wastested in 10 repetitions, and the average was converted from grams per4-inch width to grams per 3-inch width based on the essentially linearrelationship between the inter-layer peel strength and the width of theroll.

TABLE 1 Inter-Layer Peel Strength MB (grams Add- per on MB Winder MBAdh. 3-inch Sample RSTS (gsm) Type (fpm) PIH (RPM) width) 1 60 2.5PF-015 94 NA NA 126 2 60 2.5 PF-015 94 NA 8.3 170 3 120 4.9 PF-015 74 NA6.6 116 4 120 4.9 PF-015 74 NA NA 155 5 60 4.9 VM 94 0.75 6.6 35 6 1204.9 VM 74 0.75 6.6 47 7 60 4.9 VM 94 0.75 NA 14 8 120 4.9 VM 74 0.75 NA13 9 60 2.5 VM 94 0.38 NA 29 10 120 2.5 VM 74 0.38 6.6 47 11 120 4.9 VM74 0.75 6.6 47 12 60 2.5 VM 94 0.38 8.3 47

The test data provided in Table 1 indicates the elastic meltblown facingusing VISTAMAXX does not roll block. More particularly, the VISTAMAXXsamples had significantly lower inter-layer peel strength, around 13-47grams per 3-inch width versus 116-170 grams per 3-inch width withoutVISTAMAXX. This demonstrates that samples made with VISTAMAXX have lessprobability of roll blocking.

In a second alternative embodiment of a method for making a single sidefacing stretch bonded laminate, a vertical oriented extrusion platformmay be used to extrude an elastic continuous filament array. In thisembodiment, a non-tacky adhesive bonding method may be employed to bondthe elastic continuous filament array to the facing material.

FIG. 6 schematically illustrates a vertical filament laminatemanufacturing process 100 for the manufacture of elastic laminates 170produced from an elastic composition. Referring to FIG. 6, at least onemolten elastomeric material 105, i.e. a styrenic block co-polymermaterial, is extruded from a die extruder 110 through spinning holes asa plurality of substantially continuous elastomeric filaments. Theextruder may be extruding at temperatures between about 360 and 500° F.A film die for producing sheets or ribbons may also be used inalternative embodiments. The filaments 105 are quenched and solidifiedby passing the filaments 105 over a first chill roll 120. Any number ofchill rolls can be used. Suitably, chill rolls may have a temperature ofbetween about 40° F. to about 80° F.

The die of the extruder 110 may be positioned with respect to the firstroll so that the continuous filaments meet this first roll 120 at apredetermined angle 130. This strand extrusion geometry is particularlyadvantageous for depositing a melt extrudate onto a rotating roll ordrum. An angled, or canted orientation provides an opportunity for thefilaments to emerge from the die at a right angle to the roll tangentpoint, resulting in improved spinning, more efficient energy transfer,and generally longer die life. This configuration allows the filamentsto emerge at an angle from the die and follow a relatively straight pathto contact the tangent point on the roll surface. The angle 130 betweenthe die exit of the extruder 110 and the vertical axis (or thehorizontal axis of the first roll, depending on which angle is measured)may be as little as a few degrees or as much as 90 degrees. For example,a 90 degree extrudate exit to roll angle could be achieved bypositioning the extruder 110 directly above the downstream edge of thefirst roll 120 and having a side exit die tip on the extruder. Moreover,angles such as about 20 degrees, about 35 degrees, or about 45 degrees,away from vertical may be utilized. It has been found that, whenutilizing a 12-filament/inch spinplate hole density, an approximately 45degree angle (shown in FIG. 6) allows the system to operate effectively.The optimum angle, however, may vary as a function of extrudate exitvelocity, roll speed, vertical distance from the die to the roll, andhorizontal distance from the die centerline to the top dead center ofthe roller. Optimal performance can be achieved by employing variousgeometries to result in improved spinning efficiency and reducedfilament breakage.

After the filaments 105 are quenched and solidified they are stretchedor elongated using a first series of stretch rolls 140. The first seriesof stretch rolls may comprise one or more individual stretch rolls 145,150 which rotate at a speed greater than a speed at which chill roll 120rotates, thereby stretching the filaments 105.

In one embodiment of this invention, each successive roll rotates at aspeed greater than the speed of the previous roll. For example,referring to FIG. 6, if the chill roll 120 rotates at a speed “x”;stretch roll 145 rotates at a still greater speed, for example about1.15x; second stretch roll 150 rotates at a still greater speed, forexample about 1.25x to about 7x. As a result, the filaments 105 may bestretched by about 100% to about 800% of an initial pre-stretchedlength.

After the filaments 105 are stretched, the filaments 105 and themeltblown layer 152 are laminated to a facing material 155 (whenfilaments are still in a stretched condition, as similarly described inthe horizontal platform previously) by an adhesive process asexemplified by the illustrated adhesive distribution unit 160, shown asapplying adhesive to the facing material 155. The meltblown layer 152may be applied to the filaments from extrusion bank 153 between thefacing material 155 and the filaments 105, as shown in FIG. 6.

The facing material 155 is unwound from a roll 154 and laminated to afirst side of the filaments 105. Before the facing material 155 islaminated to the filaments, it may be necked by additional rolls (notshown). As previously described, the facing material may be a nonwovenmaterial, or laminates thereof, according to the present invention. Thelaminate material is then passed through nip rolls 165 to bond theelastic filaments 105 and the meltblown layer 152 to the facing 155 byadhesion. The nip rolls 165, may alternatively be used in place of, orin addition to, the stretch rolls 145, 150 to achieve stretching. Thelaminate material is then allowed to relax thereby allowing theretracting elastomeric filaments to form gathers in the laminatematerial, as with the previously described horizontal manufacturingplatform. It should be noted that in an alternative embodiment,additional relatively low open time adhesive (or nonblocking agent) 161can be applied following the exit of the bonded elastic layer and facingfrom a nip 165, such than an additional layer of non-tacky material isdeposited on the elastic layer on a side opposite to that of the facinglayer, desirably while such laminate is in the stretched condition.

The nip rollers may be designed to provide a patterned roller which mayyield certain benefits such as increased bulk or stretching of thelaminate and may be used where the strength of the contact adhesionbetween the facing and the strands is not unduly affected. The calenderrolls can be heated to a degree below the melting/softening points ofthe various laminate components, or may be ambient, or chilled.

Such single sided facing stretch bonded laminate materials haveparticular effectiveness for use in personal care products to provideelastic attributes to such products. Such single sided facing materialscan provide higher extensibility in either the MD or CD direction than alaminate with facings applied to two opposing surfaces of an elasticlayer, and can also provide a highly corrugated appearance and a softerfeel.

Such material may be useful in providing elastic waist, legcuff/gasketing, stretchable ear, side panel or stretchable outer coverapplications. While not intending to be limiting, FIG. 7 is presented toillustrate the various components of a personal care product, such as adiaper, that may take advantage of such elastic materials. Otherexamples of personal care products that may incorporate such materialsare training pants (such as in side panel materials) and feminine careproducts. By way of illustration only, training pants suitable for usewith the present invention and various materials and methods forconstructing the training pants are disclosed in PCT Patent ApplicationWO 00/37009 published Jun. 29, 2000 by A. Fletcher et al; U.S. Pat. No.4,940,464 issued Jul. 10, 1990 to Van Gompel et al.; U.S. Pat. No.5,766,389 issued Jun. 16, 1998 to Brandon et al.; and U.S. Pat. No.6,645,190 issued Nov. 11, 2003 to Olson et al., which are eachincorporated herein by reference in its entirety.

With reference to FIG. 7, the disposable diaper 250 generally defines afront waist section 255, a rear waist section 260, and an intermediatesection 265 which interconnects the front and rear waist sections. Thefront and rear waist sections 255 and 260 include the general portionsof the diaper which are constructed to extend substantially over thewearer's front and rear abdominal regions, respectively, during use. Theintermediate section 265 of the diaper includes the general portion ofthe diaper that is constructed to extend through the wearer's crotchregion between the legs. Thus, the intermediate section 265 is an areawhere repeated liquid surges typically occur in the diaper.

The diaper 250 includes, without limitation, an outer cover, orbacksheet 270, a liquid permeable bodyside liner, or topsheet, 275positioned in facing relation with the backsheet 270, and an absorbentcore body, or liquid retention structure, 280, such as an absorbent pad,which is located between the backsheet 270 and the topsheet 275. Thebacksheet 270 defines a length, or longitudinal direction 286, and awidth, or lateral direction 285 which, in the illustrated embodiment,coincide with the length and width of the diaper 250. The liquidretention structure 280 generally has a length and width that are lessthan the length and width of the backsheet 270, respectively. Thus,marginal portions of the diaper 250, such as marginal sections of thebacksheet 270 may extend past the terminal edges of the liquid retentionstructure 280. In the illustrated embodiments, for example, thebacksheet 270 extends outwardly beyond the terminal marginal edges ofthe liquid retention structure 280 to form side margins and end marginsof the diaper 250. The topsheet 275 is generally coextensive with thebacksheet 270 but may optionally cover an area which is larger orsmaller than the area of the backsheet 270, as desired.

To provide improved fit and to help reduce leakage of body exudates fromthe diaper 250, the diaper side margins and end margins may beelasticized with suitable elastic members, as further explained below.For example, as representatively illustrated in FIG. 7, the diaper 250may include leg elastics 290 which are constructed to operably tensionthe side margins of the diaper 250 to provide elasticized leg bandswhich can closely fit around the legs of the wearer to reduce leakageand provide improved comfort and appearance. Waist elastics 295 areemployed to elasticize the end margins of the diaper 250 to provideelasticized waistbands. The waist elastics 295 are configured to providea resilient, comfortably close fit around the waist of the wearer.

The single sided stretch bonded laminates of the inventive structure andmethods are suitable for use as the leg elastics 290 and waist elastics295. Exemplary of such materials are laminate sheets which eithercomprise or are adhered to the backsheet, such that elastic constrictiveforces are imparted to the backsheet 270.

As is known, fastening means, such as hook and loop fasteners, may beemployed to secure the diaper 250 on a wearer. Alternatively, otherfastening means, such as buttons, pins, snaps, adhesive tape fasteners,cohesives, fabric-and-loop fasteners, or the like, may be employed. Inthe illustrated embodiment, the diaper 250 includes a pair of sidepanels 300 (or ears) to which the fasteners 302, indicated as the hookportion of a hook and loop fastener, are attached. Generally, the sidepanels 300 are attached to the side edges of the diaper in one of thewaist sections 255, 260 and extend laterally outward therefrom. The sidepanels 300 may be elasticized or otherwise rendered elastomeric by useof a single sided stretch bonded laminate made from the inventivestructure. Examples of absorbent articles that include elasticized sidepanels and selectively configured fastener tabs are described in PCTPatent Application No. WO 95/16425 to Roessler; U.S. Pat. No. 5,399,219to Roessler et al.; U.S. Pat. No. 5,540,796 to Fries; and U.S. Pat. No.5,595,618 to Fries each of which is hereby incorporated by reference inits entirety.

The diaper 250 may also include a surge management layer 305, locatedbetween the topsheet 275 and the liquid retention structure 280, torapidly accept fluid exudates and distribute the fluid exudates to theliquid retention structure 280 within the diaper 250. The diaper 250 mayfurther include a ventilation layer (not illustrated), also called aspacer, or spacer layer, located between the liquid retention structure280 and the backsheet 270 to insulate the backsheet 270 from the liquidretention structure 280 to reduce the dampness of the garment at theexterior surface of a breathable outer cover, or backsheet, 270.Examples of suitable surge management layers 305 are described in U.S.Pat. No. 5,486,166 to Bishop and U.S. Pat. No. 5,490,846 to Ellis.

As representatively illustrated in FIG. 7, the disposable diaper 250 mayalso include a pair of containment flaps 310 which are configured toprovide a barrier to the lateral flow of body exudates. The containmentflaps 310 may be located along the laterally opposed side edges of thediaper adjacent the side edges of the liquid retention structure 280.Each containment flap 310 typically defines an unattached edge which isconfigured to maintain an upright, perpendicular configuration in atleast the intermediate section 265 of the diaper 250 to form a sealagainst the wearer's body. The containment flaps 310 may extendlongitudinally along the entire length of the liquid retention structure280 or may only extend partially along the length of the liquidretention structure. When the containment flaps 310 are shorter inlength than the liquid retention structure 280, the containment flaps310 can be selectively positioned anywhere along the side edges of thediaper 250 in the intermediate section 265. Such containment flaps 310are generally well known to those skilled in the art. For example,suitable constructions and arrangements for containment flaps 310 aredescribed in U.S. Pat. No. 4,704,116 to K. Enloe.

The diaper 250 may be of various suitable shapes. For example, thediaper may have an overall rectangular shape, T-shape or anapproximately hour-glass shape. In the shown embodiment, the diaper 250has a generally I-shape. Other suitable components which may beincorporated on absorbent articles of the present invention may includewaist flaps and the like which are generally known to those skilled inthe art. Examples of diaper configurations suitable for use inconnection with the instant invention which may include other componentssuitable for use on diapers are described in U.S. Pat. No. 4,798,603 toMeyer et al.; U.S. Pat. No. 5,176,668 to Bemardin; U.S. Pat. No.5,176,672 to Bruemmer et al.; U.S. Pat. No. 5,192,606 to Proxmire et al.and U.S. Pat. No. 5,509,915 to Hanson et al. each of which is herebyincorporated by reference in its entirety.

The various components of the diaper 250 are assembled togetheremploying various types of suitable attachment means, such as adhesivebonding, ultrasonic bonding, thermal point bonding or combinationsthereof. In the shown embodiment, for example, the topsheet 275 andbacksheet 270 may be assembled to each other and to the liquid retentionstructure 280 with lines of adhesive, such as a hot melt,pressure-sensitive adhesive. Similarly, other diaper components, such asthe elastic members 290 and 295, fastening members 302, and surge layer305 may be assembled into the article by employing the above-identifiedattachment mechanisms.

It should be appreciated that such single side facing stretch bondedlaminate materials may likewise be used in other personal care products,protective outerwear, protective coverings and the like. Further suchmaterials can be used in bandage materials for both human and animalbandaging products. Use of such materials provide acceptable elasticperformance at a-lower manufacturing cost.

These and other modifications and variations to the present inventionmay be practiced by those of ordinary skill in the art, withoutdeparting from the spirit and scope of the present invention, which ismore particularly set forth in the appended claims. In addition, itshould be understood that aspects of the various embodiments may beinterchanged both in whole or in part. Furthermore, those of ordinaryskill in the art will appreciate that the foregoing description is byway of example only, and is not intended to limit the invention sofurther described in such appended claims.

Test Method Procedures

Stretch-to-Stop Test

“Stretch-to-stop” refers to a ratio determined from the differencebetween the unextended dimension of a stretchable laminate and themaximum extended dimension of a stretchable laminate upon theapplication of a specified tensioning force and dividing that differenceby the unextended dimension of the stretchable laminate. If thestretch-to-stop is expressed in percent, this ratio is multiplied by100. For example, a stretchable laminate having an unextended length of5 inches (12.7 cm) and a maximum extended length of 10 inches (25.4 cm)upon applying a force of 750 grams has a stretch-to-stop (at 750 grams)of 100 percent. Stretch-to-stop may also be referred to as “maximumnon-destructive elongation.” Unless specified otherwise, stretch-to-stopvalues are reported herein at a load of 750 grams. In the elongation orstretch-to-stop test, a 3-inch by 7-inch (7.62 cm by 17.78 cm) sample,with the larger dimension being the machine direction, the crossdirection, or any direction in between, is placed in the jaws of aSintech machine using a gap of 5 cm between the jaws. The sample is thenpulled to a stop load of 750 gms with a crosshead speed of about 20inches/minute (50.8 cm/minute). For the stretchable laminate material ofthis invention, it is desirable that it demonstrate a stretch to stopvalue between about 30-400 percent, alternatively between about 50 and300 percent, still in a further alternative, between about 80-250percent. The stretch to stop test is done in the direction ofextensibility (stretch). Depending upon the material being tested, agreater applied force may be more appropriate. For example, for a singlefaced laminate the applied force of 750 grams per 3 inchcross-directional width is typically appropriate; however, for certainlaminates, particularly higher basis weight laminates, an applied forcebetween 750 and 2000 grams per 3 inch cross-directional width may bemost appropriate.

Roll-Blocking Test Method (for Inter-layer Peel Strength of LaminateLayers off of a Roll)

An approximately 50 inch outer diameter roll of single sided stretchbonded laminate was cut along the cross or transverse direction from thetop of a roll to the core with a utility knife. Three sections ofmaterial from the top, the core and a midpoint of the radius were usedas samples. Each sample was approximately 18 inches by 24 inches andcontained approximately 30 undisturbed layers of laminate. From each ofthese samples, eight 3 inch wide by 7 inch long specimens were cut, withthe 7 inch being in the machine direction. Each specimen contained 2layers of laminate (with each laminate including an elastic layer and asingle facing layer). The upper layer of one end of the specimen (a fulllaminate of an elastic layer and facing) was loaded into the upper jawof a tensile testing unit (Sintech) while the lower layer of thespecimen (a full laminate of an elastic layer and facing) from the sameend of the specimen as used for the upper layer, was loaded into thelower jaw of the Sintech unit. Using the method described generallybelow, the Sintech tensile tester (manufactured by MTS Systems Corp.,model Synergie 200) was used to measure the average force along the MDlength of the material required to separate the two layers, at a 180degree angle and at a strain rate of 300 mm/min. All specimens weretested in the machine direction. For the samples tested, the polymerused for the filaments in the roll (of continuous filaments) was KRATONG2755, as will be described below. The basis weight ratio of strands tomeltblown in the elastic layer was about 90:10. Eight specimens wereused and the average value of these was taken as the accepted peelvalue.

Essentially the test measures the force required to separate twocomplete layers of single sided stretch bonded laminate material fromeach other (simulating unwinding of laminate from a supply roll). It isconsidered that such force would be representative of the forcenecessary to pull a layer of a rolled material off of the roll. Resultsare expressed in units of grams of force, with higher numbersrepresenting a tackier fabric, which adheres to itself on a roll. Forthe materials of the present invention, in one embodiment, the materialdemonstrates a peel strength of less than 200 g. For an alternativeembodiment, the material demonstrates a peel strength of less than 100g. In still a further alternative embodiment, the material demonstratesa peel strength of less than 50 g.

In conducting the test, the individual plies of the laminate fabric(that is one single sided laminate and another) are manually separatedfor a distance of approximately 2-3 inches to give at least 4 inches ofworking direction, or separation length. One ply of the sample specimenfrom the same end of the specimen is clamped into each jaw of thetensile tester and the specimen is then subjected to a constant rate ofextension. The edges of the sample are desirably clean cut and parallel.Desirably Sintech TestWorks software can be utilized to acquire data forthe system. The grips include 1 inch by 4 inch jaw faces, where the 4inch dimension is the width of the jaw. The tests are conducted atstandard laboratory atmosphere-ambient conditions. The sample of thetest should measure from about 3-4 inches in the CD and at least 6inches in the MD. An appropriate load cell should be chosen such thatthe peak load value will fall between 10 and 90 percent of the fullscale load, 25 lbs or less. Desirably a 5 lb load cell is used.Desirably, where possible, the measurement should be started at about 16mm and ended up to about 170 mm of elongation. The gage length should beset at about 2 inches (distance between jaws).

1. An elastic single sided stretch bonded laminate comprising: anelastic layer comprising an array of continuous filament strands with anelastic meltblown layer deposited on said continuous filament strands,wherein the elastic meltblown layer comprises an elasticpolyolefin-based meltblown polymer having a degree of crystallinitybetween about 3% and about 40%, the polyolefin-based meltblown polymercomprises at least one of the group consisting of ethylene methacrylate,polyisobutylene and butyl acrylate; and a facing layer bonded to onlyone side of said elastic layer; wherein the laminate has an inter-layerpeel strength of less than about 70 grams per 3 inches cross-directionalwidth at a strain rate of 300 mm/min and eliminates roll blocking. 2.The elastic laminate of claim 1, wherein the elastic polyolefin-basedmeltblown polymer has a melt flow rate between about 10 and about 600grams per 10 minutes.
 3. The elastic laminate of claim 1, wherein theelastic polyolefin-based meltblown polymer has a melting/softening pointbetween about 40 and about 160 degrees Celsius.
 4. The elastic laminateof claim 1, wherein the elastic polyolefin-based meltblown polymer has adensity from about 0.8 to about 0.95 grams per cubic centimeter.
 5. Theelastic laminate of claim 1, wherein the laminate does not include anonblocking agent applied to the laminate as a post-calender treatment.6. The elastic laminate of claim 1, further comprising an adhesive thatdemonstrates a relatively short open time deposited between the array ofcontinuous filament strands and the elastic meltblown layer, wherein theopen time of the adhesive is between about 0.2 seconds and 1 minute. 7.The elastic laminate of claim 1, wherein the elastic meltblown layer isdeposited at an add-on between about 1 and about 5 grams per squaremeter during lamination.
 8. An elastic single sided stretch bondedlaminate comprising: an elastic layer comprising an array of continuousfilament strands with a meltblown layer deposited on said continuousfilament strands, wherein the continuous filament strands comprise anelastic polyolefin-based polymer having a degree of crystallinitybetween about 3% and about 40%, the continuous filament strands compriseat least one of the group consisting of ethylene methacrylate,polyisobutylene, and butyl acrylate; an adhesive that demonstrates arelatively short open time deposited between the array of continuousfilament strands and the meltblown layer, wherein the open time of theadhesive is between about 0.2 seconds and 1 minute; and a facing layerbonded to only one side of said elastic layer; wherein the laminate hasan inter-layer peel strength of less than about 70 grams per 3 inchescross-directional width at a strain rate of 300 mm/min and eliminatesroll blocking.
 9. The elastic laminate of claim 8, wherein the elasticpolyolefin-based polymer has a melt flow rate between about 10 and about600 grams per 10 minutes.
 10. The elastic laminate of claim 8, whereinthe elastic polyolefin-based polymer has a melting/softening pointbetween about 40 and about 160 degrees Celsius.
 11. The elastic laminateof claim 8, wherein the elastic polyolefin-based polymer has a densityfrom about 0.8 to about 0.95 grams per cubic centimeter.
 12. The elasticlaminate of claim 8, wherein the meltblown layer comprises an elasticpolyolefin-based meltblown polymer having a degree of crystallinitybetween about 3% and about 40%.
 13. The elastic laminate of claim 8,wherein the laminate does not include a nonblocking agent applied to thelaminate as a post-calender treatment.
 14. The elastic laminate of claim8, wherein the meltblown layer comprises at least two layers, with afirst layer comprising an elastic polyolefin-based meltblown polymerhaving a degree of crystallinity between about 3% and about 40% and asecond layer comprising a styrenic block copolymer-based meltblownpolymer.
 15. The elastic laminate of claim 8, wherein the meltblownlayer is deposited at an add-on between about 1 and about 5 grams persquare meter during lamination.
 16. An elastic single sided stretchbonded laminate comprising: an elastic layer comprising an array ofcontinuous filament strands with a meltblown layer deposited on saidcontinuous filament strands, wherein the meltblown layer comprises atleast two layers, with a first layer comprising an elasticpolyolefin-based meltblown polymer having a degree of crystallinitybetween about 3% and about 40% and a second layer comprising a styrenicblock copolymer-based meltblown polymer, the elastic polyolefinmeltblown polymer comprises at least one of the group consisting ofethylene methacrylate, polyisobutylene and butyl acrylate; and a facinglayer bonded to only one side of said elastic layer, wherein the facinglayer comprises an elastic polyolefin-based polymer having a degree ofcrystallinity between about 3% and about 40%; wherein the laminate hasan inter-layer peel strength of less than about 70 grams per 3 inchescross-directional width at a strain rate of 300 mm/min and eliminatesroll blocking.
 17. The elastic laminate of claim 16, wherein the facinglayer comprises a spunbond-meltblown-spunbond laminate in which theelastic polyolefin-based polymer of the facing layer is meltblown andpositioned between two spunbond layers.
 18. The elastic laminate ofclaim 16, wherein the meltblown layer is deposited at an add-on betweenabout 1 and about 5 grams per square meter during lamination.
 19. Anelastic single sided stretch bonded laminate comprising: an elasticlayer comprising an array of continuous filament strands with an elasticmeltblown layer deposited on said continuous filament strands, themeltblown layer comprises at least one of the group consisting ofethylene methacrylate, polyisobutylene and butyl acrylate; an adhesivethat demonstrates a relatively short open time deposited between thearray of continuous filament strands and the elastic meltblown layer,wherein the open time of the adhesive is between about 0.2 seconds and 1minute; and a facing layer bonded to only one side of said elasticlayer; wherein the laminate has an inter-layer peel strength of lessthan about 70 grams per 3 inches cross-directional width at a strainrate of 300 mm/min and eliminates roll blocking.
 20. The elasticlaminate of claim 19, wherein the elastic meltblown layer comprises anelastic polyolefin-based meltblown polymer having a degree ofcrystallinity from about 3% to about 40%.
 21. The elastic laminate ofclaim 19, wherein the elastic meltblown layer is deposited at an add-onbetween about 1 and about 5 grams per square meter during lamination.22. An elastic single sided stretch bonded laminate comprising: anelastic layer comprising an array of continuous filament strands with ameltblown layer deposited on said continuous filament strands, whereinthe continuous filament strands comprise an elastic polyolefin-basedpolymer having a degree of crystallinity between about 3% and about 40%,and the meltblown layer comprises at least two layers, with a firstlayer comprising an elastic polyolefin-based meltblown polymer having adegree of crystallinity between about 3% and about 40% and a secondlayer comprising a styrenic block copolymer-based meltblown polymers,the first layer comprises at least one of the group consisting ofethylene methacrylate, polyisobutylene and butyl acrylate; and a facinglayer bonded to only one side of said elastic layer; wherein thelaminate has an inter-layer peel strength of less than about 70 gramsper 3 inches cross-directional width at a strain rate of 300 mm/min andeliminates roll blocking.
 23. The elastic laminate of claim 22, whereinthe elastic polyolefin-based polymer in the continuous filament strandshas a melt flow rate between about 10 and about 600 grams per 10minutes.
 24. The elastic laminate of claim 22, wherein the elasticpolyolefin-based polymer in the continuous filament strands has amelting/softening point between about 40 and about 160 degrees Celsius.25. The elastic laminate of claim 22, wherein the elasticpolyolefin-based polymer in the continuous filament strands has adensity from about 0.8 to about 0.95 grams per cubic centimeter.
 26. Theelastic laminate of claim 1, wherein the elastic meltblown layercomprises at least two layers, with a first layer comprising an elasticpolyolefin-based meltblown polymer having a degree of crystallinitybetween about 3% and about 40% and a second layer comprising a styrenicblock copolymer-based meltblown polymer.
 27. The elastic laminate ofclaim 1, further comprising an intra-layer peel strength of about 200 toabout 450 grams per 3 inches cross-directional width at a strain rate of300 mm/min.
 28. The elastic laminate of claim 1, further comprising anadhesive that demonstrates a relatively short open time depositedbetween the array of continuous filament strands and the elasticmeltblown layer, wherein the open time of the adhesive is between about0.2 seconds and 3 seconds.
 29. The elastic laminate of claim 28, whereinthe adhesive comprises a polypropylene-based hot melt adhesive.